C43 2017 knocking sound from left bank only
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C43 w205 sedan
C43 2017 knocking sound from left bank only
Purchased a C43 sedan, 2017 at 178000km. The vehicle seems really good and healthy compared to the kilometers, however I'm a bit worried about one particular noise from the engine.
After cold start when the rpm drops to the normal idle level, I can hear a knocking sound that quite distinctly comes from the left bank of the engine (viewed from the front of the car). It's very noticeable when listening with a screwdriver and connecting it to the left valve cover. It's so powerful that it almost hurts my ear when I listen through the screwdriver and I can also feel a sharp impulse in my fingers. What bothers me the most is that the right bank seems pretty much silent in this regard (also no feedback to the fingers there). Of course both of the banks have that typical healthy timing chain whirring sound, but on the left bank there is also the knocking that is clearly a separate noise.
I can't hear any timing chain slap when cold starting the engine. To me that knocking rather sounds like a valve thing. What do you think?
From the cabin I can hear something that I think is the same noise, but becomes more muted obviously. So the idle sounds like sort of deep and soft knocking from inside the car too. I can't hear the noise when I rev the engine even a tiny bit. Just to be clear, AC is turned off so it's not that. Also this is not a purge valve, I know how it sounds like and it's located in a totally different side of the engine.
The noise fades a lot when the engine warms up but is not completely silent.
Better when listened with a decent headphones:
https://www.dropbox.com/scl/fi/gyn7n...=wvplk8uq&dl=0
Also found these from Youtube, sounds pretty much or exactly like these two:
After cold start when the rpm drops to the normal idle level, I can hear a knocking sound that quite distinctly comes from the left bank of the engine (viewed from the front of the car). It's very noticeable when listening with a screwdriver and connecting it to the left valve cover. It's so powerful that it almost hurts my ear when I listen through the screwdriver and I can also feel a sharp impulse in my fingers. What bothers me the most is that the right bank seems pretty much silent in this regard (also no feedback to the fingers there). Of course both of the banks have that typical healthy timing chain whirring sound, but on the left bank there is also the knocking that is clearly a separate noise.
I can't hear any timing chain slap when cold starting the engine. To me that knocking rather sounds like a valve thing. What do you think?
From the cabin I can hear something that I think is the same noise, but becomes more muted obviously. So the idle sounds like sort of deep and soft knocking from inside the car too. I can't hear the noise when I rev the engine even a tiny bit. Just to be clear, AC is turned off so it's not that. Also this is not a purge valve, I know how it sounds like and it's located in a totally different side of the engine.
The noise fades a lot when the engine warms up but is not completely silent.
Better when listened with a decent headphones:
https://www.dropbox.com/scl/fi/gyn7n...=wvplk8uq&dl=0
Also found these from Youtube, sounds pretty much or exactly like these two:
Last edited by J_h; Today at 08:33 AM.
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
Purchased a C43 sedan, 2017 at 178000km. The vehicle seems really good and healthy compared to the kilometers, however I'm a bit worried about one particular noise from the engine.
After cold start when the rpm drops to the normal idle level, I can hear a knocking sound that quite distinctly comes from the left bank of the engine (viewed from the front of the car). It's very noticeable when listening with a screwdriver and connecting it to the left valve cover. It's so powerful that it almost hurts my ear when I listen through the screwdriver and I can also feel a sharp impulse in my fingers. What bothers me the most is that the right bank seems pretty much silent in this regard (also no feedback to the fingers there). Of course both of the banks have that typical healthy timing chain whirring sound, but on the left bank there is also the knocking that is clearly a separate noise.
I can't hear any timing chain slap when cold starting the engine. To me that knocking rather sounds like a valve thing. What do you think?
From the cabin I can hear something that I think is the same noise, but becomes more muted obviously. So the idle sounds like sort of deep and soft knocking from inside the car too. I can't hear the noise when I rev the engine even a tiny bit. Just to be clear, AC is turned off so it's not that. Also this is not a purge valve, I know how it sounds like and it's located in a totally different side of the engine.
The noise fades a lot when the engine warms up but is not completely silent.
Better when listened with a decent headphones:
https://www.dropbox.com/scl/fi/gyn7n...=wvplk8uq&dl=0
Also found these from Youtube, sounds pretty much or exactly like these two:
https://youtu.be/z3r-40eAa4I?feature=shared
https://youtu.be/Y4V-JV0Zvm0?feature=shared
After cold start when the rpm drops to the normal idle level, I can hear a knocking sound that quite distinctly comes from the left bank of the engine (viewed from the front of the car). It's very noticeable when listening with a screwdriver and connecting it to the left valve cover. It's so powerful that it almost hurts my ear when I listen through the screwdriver and I can also feel a sharp impulse in my fingers. What bothers me the most is that the right bank seems pretty much silent in this regard (also no feedback to the fingers there). Of course both of the banks have that typical healthy timing chain whirring sound, but on the left bank there is also the knocking that is clearly a separate noise.
I can't hear any timing chain slap when cold starting the engine. To me that knocking rather sounds like a valve thing. What do you think?
From the cabin I can hear something that I think is the same noise, but becomes more muted obviously. So the idle sounds like sort of deep and soft knocking from inside the car too. I can't hear the noise when I rev the engine even a tiny bit. Just to be clear, AC is turned off so it's not that. Also this is not a purge valve, I know how it sounds like and it's located in a totally different side of the engine.
The noise fades a lot when the engine warms up but is not completely silent.
Better when listened with a decent headphones:
https://www.dropbox.com/scl/fi/gyn7n...=wvplk8uq&dl=0
Also found these from Youtube, sounds pretty much or exactly like these two:
https://youtu.be/z3r-40eAa4I?feature=shared
https://youtu.be/Y4V-JV0Zvm0?feature=shared
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Here I tried to isolate the noise with a video editing software and now it's pretty obvious at least if you know what to listen. Now the sound breaks and sounds kind of high pitched at times because the phone mic can't handle it (my phone was basically touching the screwdriver head).
https://www.dropbox.com/scl/fi/ol1qi...=dlakphaf&dl=0
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
Sounds pretty much exactly like those c300. I don't think youtube makes any difference. I had this issue with my friend too, he didn't hear it and it seems to depend on the device you're listening on, but his headphones were absolute crap. I can hear it on my phone, monitor speakers and headphones though..
Here I tried to isolate the noise with a video editing software and now it's pretty obvious at least if you know what to listen. Now the sound breaks and sounds kind of high pitched at times because the phone mic can't handle it (my phone was basically touching the screwdriver head).
https://www.dropbox.com/scl/fi/ol1qi...=dlakphaf&dl=0
Here I tried to isolate the noise with a video editing software and now it's pretty obvious at least if you know what to listen. Now the sound breaks and sounds kind of high pitched at times because the phone mic can't handle it (my phone was basically touching the screwdriver head).
https://www.dropbox.com/scl/fi/ol1qi...=dlakphaf&dl=0
See if this is similar to your sound : https://mbworld.org/forums/e-class-w...76-engine.html
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
If you need further assistance, forum member CaliBenzDriver is the M276 expert and he will be more than happy to help you : )
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Sorry about that, maybe I have bad ears.
See if this is similar to your sound : https://mbworld.org/forums/e-class-w...76-engine.html
See if this is similar to your sound : https://mbworld.org/forums/e-class-w...76-engine.html
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
Forum member CaliBenzDriver calls it a tapping sound.
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Yeah it seems like the whole discussion turned into oil viscosity but the tap tap tap noise never got explained further.
Seems like there is the water pump attached to the left cylinder bank side (mostly) so I might want to suspect that too. But it's a bit more tricky to listen to..
Seems like there is the water pump attached to the left cylinder bank side (mostly) so I might want to suspect that too. But it's a bit more tricky to listen to..
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
Yeah it seems like the whole discussion turned into oil viscosity but the tap tap tap noise never got explained further.
Seems like there is the water pump attached to the left cylinder bank side (mostly) so I might want to suspect that too. But it's a bit more tricky to listen to..
Seems like there is the water pump attached to the left cylinder bank side (mostly) so I might want to suspect that too. But it's a bit more tricky to listen to..
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The belt area seems impossible to listen with the screwdriver method, it's so packed. But I listened from the rear end of the valve cover and the noise is loud there, perhaps even louder than from the chain side. Something tells me it's not the pulleys.
New video:
https://www.dropbox.com/scl/fi/g19u8...=ul9tutzh&dl=0
New video:
https://www.dropbox.com/scl/fi/g19u8...=ul9tutzh&dl=0
Last edited by J_h; Today at 12:45 PM.
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
The belt area seems impossible to listen with the screwdriver method, it's so packed. But I listened from the rear end of the valve cover and the noise is loud there, perhaps even louder than from the chain side. Something tells me it's not the pulleys.
New video:
https://www.dropbox.com/scl/fi/g19u8...=do09lcjg&dl=0
New video:
https://www.dropbox.com/scl/fi/g19u8...=do09lcjg&dl=0
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
OP, I finally hear what you are talking about. I will need to compare the sound next time I drive my vehicle in a week. In the meantime, hopefully someone chimes in soon.